Software giant Microsoft and the leading online retailer Amazon.com have said they are joining forces to sell digital books.

Under the deal, Microsoft will supply Amazon with a customised version of its Reader software that allows consumers to download and display text on personal computers or handheld devices.

Dick Brass, Microsoft's vice-president of technology development, said the partnership between the two companies would "evolve the reading experience" and make electronic reading "a powerful new reality."

Amazon, the world's top internet bookseller, said it hoped to be able to offer thousands of titles in its digital bookstore.

Digital advantages

"E-books are an exciting new way to read that combines the transforming qualities of literature with the unique advantages of the digital realm," said Amazon books general manager, Lyn Blake.

Microsoft said that up to 100,000 titles could be on sale in digital form by the end of next year.

"It is very important to ramp up very quickly the number of titles so e-books aren't seen as sort of a toy or niche," Mr Brass said.

At present, digital book sales account for a tiny fraction of total industry sales.

Horror online

But several high-profile attempts to popularise the medium have been made in recent months including the publication online of the latest book by horror writer Stephen King.

Microsoft claims that software technology has also been improved, making text easier to read and reducing eye strain.

Mr Brass cited analyst forecasts that digital book sales could reach $3bn a year, or 10% of total book sales, by the end of 2005.

The Amazon deal is the second digital books partnership for Microsoft.

Earlier in August, it said it was teaming up with the online division of US bookseller Barnes & Noble to create the first major internet seller of digital books.